OXYGEN DEVICES BARRED ON FLIGHTS

David S. Cloud, Washington BureauCHICAGO TRIBUNE

U.S. TEMPORARILY BANS TRANSPORT OF CANISTERS SUSPECTED IN CRASH

The Transportation Department announced Thursday that passenger planes would be temporarily barred from ferrying oxygen generators, the devices investigators suspect contributed to a fire on ValuJet Flight 592.

Oxygen-creating canisters are installed on passenger planes to feed emergency masks if the cabin decompresses. The ban applies only when the canisters are carried as cargo and will last until the end of the year while the department reviews rules governing airborne hazardous material.

The canisters contain volatile oxygen-producing chemicals and can reach temperatures as high as 500 degrees when activated. Regulations require that they be securely packaged when shipped in the holds of passenger planes.

The ban was the second move in two days by the Transportation Department and the Federal Aviation Administration to toughen federal regulations in the wake of the May 11 ValuJet crash near Miami, which killed 110 people.

On Wednesday, the FAA announced it would consider requiring smoke detectors and alarms in passenger jet cargo holds.

ValuJet records show that more than 100 of the canisters, removed from three other planes, were being shipped to Atlanta on the DC-9 that crashed. Investigators suspect that some might have accidentally discharged, causing a fire or explosion.

Investigators from the National Transportation Safety Board are continuing to interview employees at ValuJet and at Sabretech, the Phoenix-based maintenance company that removed the canisters from the three planes because their expiration date had passed.

"A hazardous materials team is still trying to determine the exact circumstances of that shipment," NTSB spokesman Pat Cariseo said.

ValuJet says its employees loaded the canisters onto the plane in boxes with labels filled out by Sabretech that said the generators were empty--and thus were no longer dangerous.

Kenneth Quinn, a Sabretech spokesman, said in a statement that "the bottom line is that ValuJet made an independent decision to ship their returned company materials on board an aircraft and apparently did not ensure that they were properly labeled, packaged, and stored."

Shipping the canisters by air after their removal is not a common industry practice, experts say. The canisters are not refillable and, if their shelf life expires, many airlines empty the canisters at the maintenance site and dispose of them immediately.

M.R. Kaletta, an executive at Scott Aviation, the largest manufacturer of oxygen generators, called discharged canisters "worthless" and said they are thrown away.

Other aviation industry officials agreed.

"Delta isn't going to ship these back to headquarters," said Michael Rioux, vice president of the Air Transport Association, which represents large carriers. "They have the capability to dispose of the (canisters) wherever they are."